1. Field of the Invention
The present invention generally relates to memory devices and more particularly, to a memory device having negative-differential conductance diodes and a threshold diode. Further, the present invention is concerned with a method for reading information from such a memory device and writing information into the memory device, and a method for producing the memory device.
Recently, there has been considerable activity in the development of large-scale semiconductor memories, such as 64 Mbit DRAMs (Dynamic Random Access Memories) and 16 Mbit SRAMs (Static Random Access Memories). However, current memory cell structures have a limited integration density, and it is hence desired to develop novel semiconductor memory cells having a higher integration density.
2. Description of the Prior Art
Generally, a memory cell of DRAMs has a capacitor which utilizes a junction capacitance of an FET (Field Effect Transistor) for storing information, and an FET for reading information from the junction capacitance and writing infomation therein. A memory cell of SRAMs has a flip-flop type memory cell structure, which is normally made up of six FETs.
The SRAM memory cell needs an area occupied by at least six FETs and hence has a limit regarding the integration density.